2. Species status information

The Rocky Mountain Sculpin (Cottus sp.) is a small, freshwater fish belonging to the predominantly marine sculpin family (Cottidae). It has also been referred to as the St. Mary Shorthead Sculpin (Alberta Sustainable Resource Development [ASRD] 2004), and the Eastslope Sculpin (Committee on the Status of Endangered Wildlife in Canada [COSEWIC] 2005; Taylor and Gow 2008). These fish are locally abundant in cool, clear reaches of the St. Mary and Milk river watersheds of Alberta. Their taxonomic relationship to other sculpins in North America is uncertain. However, the natural rarity of this taxon in Canada, in terms of both distribution and abundance, makes the sculpin vulnerable to extirpation. Elsewhere, freshwater sculpin populations have been most impacted by alterations to flow regimes particularly where riverine conditions have been replaced by lake conditions. Loss of the Rocky Mountain Sculpin from either river would be a significant loss to the species complex.

In August 2006, Rocky Mountain Sculpin, Eastslope populations in the St. Mary and Milk river watersheds of Alberta were listed as “Threatened” under Schedule 1 of the Species at Risk Act (SARA) (P.C. 2006-768 August 15, 2006). Listing afforded immediate protection for the species and required development of a recovery strategy within two years. In December 2007, the species was also listed as “Threatened” under Alberta’s Wildlife Act. Under the federal and provincial species at risk processes, Rocky Mountain Sculpin, Eastslope populations in Alberta were listed as threatened primarily because of their limited distribution, which makes them vulnerable to habitat loss or degradation.